The second-seeded former world No. 1 superstar opened defense of his titles
with a 69-minute 6-3, 6-1 spanking of helpless eighth-seeded Serb Janko
Tipsarevic indoors at The O2 Arena. The mighty Federer was not broken in the
predictable Day-2 affair, as Tipsarevic won only eight points on the Swiss'
serve in the rout.

Federer is now 40-7 lifetime at the prestigious tournament, including titles
from 2003-04, 2006-07 and the last two years.

Later Tuesday, fourth-seeded David Ferrer, fresh off his Paris Masters title
last week, will battle surging sixth-seeded Argentine slugger Juan Martin del
Potro. Ferrer was an ATP Finals runner-up to Federer in 2007. Del Potro has
titled in two of his last three events.

Wednesday's round-robin schedule will pit world No. 1 and Australian Open
champion Novak Djokovic against third-seeded Andy Murray and fifth-seeded
Czech Tomas Berdych versus seventh-seeded Jo-Wilfried Tsonga, who lost to
Federer in last year's Tour Finals finale in London. The Olympic gold medalist
Murray upended his good friend Djokovic in September's U.S. Open final.

Djokovic, who will finish as the year-end No. 1 for a second straight year,
captured this elite eight-player event in Shanghai back in 2008.

This week's four-player Group A features Djokovic (1-0), Murray (1-0), Berdych
(0-1) and Tsonga (0-1), while Group B boasts Federer (1-0), Ferrer, del
Potro and Tipsarevic (0-1). The top-two players from each group will play
in the semifinals on Sunday, and the winners will square off in the lucrative
finale Monday in London.

The 2012 World Tour Finals champion can earn as much as $1.76 million.